-LRB- CNN -RRB- -- Supreme Court Justice Clarence Thomas has released newly corrected financial disclosure forms showing his wife 's past employment , blaming a misunderstanding for years of omissions of Virginia `` Ginni '' Thomas ' salary at a conservative think tank and other jobs .

Thomas was required to report the information on the annual disclosure forms all federal judges must file . The forms did not disclose how much money Mrs. Thomas was paid .

The updated records go back 13 years and confirm Mrs. Thomas has worked for the Heritage Foundation , the Republican leadership in the House and Hillsdale College in Michigan .

Her employers were known previously , since Virginia Thomas is a well-known conservative activist . She founded her own conservative group , Liberty Central , in late 2009 . That information was also not disclosed on the justice 's financial forms . She has since relinquished leadership of Liberty Central , but still has an advisory role .

The new information came after the liberal advocacy group Common Cause noted the omissions last week . The group also urged the Justice Department to investigate whether a speech the justice gave in 2008 before a conservative seminar sponsored in part by prominent GOP fundraisers created a possible conflict of interest .

Common Cause said its review of the Heritage Foundation 's IRS forms showed Virginia Thomas earned nearly $ 700,000 from 2003-07 while at the think tank .

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Justice Thomas releases details of his wife 's past employment

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A liberal group noted that information was omitted on financial disclosure forms

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Thomas blames the omission on a misunderstanding